Unsent text is not kept

Text you have not sent, files waiting to go and the message you are replying to are kept in memory only. They are gone when KUVRT closes or reloads.

A voice message you recorded is kept until you send or delete it, also when KUVRT closes.

After you tap send, your text stays greyed in the field until it is in the chat. "Sending as soon as KUVRT is free" means it waits for something else KUVRT is doing first.